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identify the passive and active path in multipath

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skt_skt
Honored Contributor

identify the passive and active path in multipath


Red Hat Enterprise Linux AS release 4 (Nahant Update 6)

Linux hostname 2.6.9-67.ELsmp #1 SMP Wed Nov 7 13:58:04 EST 2007 i686 i686 i386 GNU/Linux

device-mapper-multipath-0.4.5-27.RHEL4
device-mapper-1.02.21-1.el4
lvm2-2.02.27-2.el4

How can i identify the passive and active path in multipath configiration.(No power path)
13 REPLIES
Ivan Ferreira
Honored Contributor
Solution

Re: identify the passive and active path in multipath

Just use the "multipath -l" command and depending of your configuration, you may have active/active paths.
Por que hacerlo dificil si es posible hacerlo facil? - Why do it the hard way, when you can do it the easy way?
skt_skt
Honored Contributor

Re: identify the passive and active path in multipath


# multipath -l
mpath0 (360060160f1731100e8ef486b8825dd11)
[size=89 GB][features="1 queue_if_no_path"][hwhandler="1 emc"]
\_ round-robin 0 [active]
\_ 3:0:1:0 sdc 8:32 [active]
\_ round-robin 0 [enabled]
\_ 3:0:0:0 sdb 8:16 [active]

Does this indicate both ar active?
skt_skt
Honored Contributor

Re: identify the passive and active path in multipath

i am trying to identify why i get these messages continuously(still coming)

Sep 22 15:20:52 hostname kernel: Device sdb not ready.
Sep 22 15:20:52 hostname kernel: end_request: I/O error, dev sdb, sector 0
Sep 22 15:20:52 hostname kernel: Buffer I/O error on device sdb, logical block 0

sdc is primary and sdb is passive( what i understood) not sure what is trying to access the passive path and why?

[root@shdbl3d ~]# lsof /dev/sdc
COMMAND PID USER FD TYPE DEVICE SIZE NODE NAME
multipath 3432 root 5r BLK 8,32 1849 /dev/sdc
[root@shdbl3d ~]# lsof /dev/sdb
COMMAND PID USER FD TYPE DEVICE SIZE NODE NAME
multipath 3432 root 4r BLK 8,16 1805 /dev/sdb

# multipath -v 3
load path identifiers cache
#
# all paths in cache :
#
360060160f1731100e8ef486b8825dd11 3:0:0:0 sdb 8:16 [active] DGC /RAID 5
360060160f1731100e8ef486b8825dd11 3:0:1:0 sdc 8:32 1 [active] DGC /RAID 5
hdc blacklisted
sda blacklisted


also what is meant by blacklisted above?
Court Campbell
Honored Contributor

Re: identify the passive and active path in multipath

The blacklisted devices are ones that you don;t want dm-mutilpath to handle. Like your local disk and cdrom.
"The difference between me and you? I will read the man page." and "Respect the hat." and "You could just do a search on ITRC, you don't need to start a thread on a topic that's been answered 100 times already." Oh, and "What. no points???"
Ivan Ferreira
Honored Contributor

Re: identify the passive and active path in multipath

¿Is this a storage with active/active controller?
Por que hacerlo dificil si es posible hacerlo facil? - Why do it the hard way, when you can do it the easy way?
skt_skt
Honored Contributor

Re: identify the passive and active path in multipath

it is emc_clariion .
Ivan Ferreira
Honored Contributor

Re: identify the passive and active path in multipath

Check if you don't have an incorrect definition for raw devices mapping in /etc/sysconfig/rawdevices, check also the output of:

raw -qa

Check also monitoring tools, like "smartd".
Por que hacerlo dificil si es posible hacerlo facil? - Why do it the hard way, when you can do it the easy way?
skt_skt
Honored Contributor

Re: identify the passive and active path in multipath

i dont have anything defined in /etc/sysconfig/rawdevices and "raw -qa" returns nothing
Court Campbell
Honored Contributor

Re: identify the passive and active path in multipath

I am kind of surprised that you are not seeing four paths to the disk. Can you post your multipath.conf file and the model of emc you have?
"The difference between me and you? I will read the man page." and "Respect the hat." and "You could just do a search on ITRC, you don't need to start a thread on a topic that's been answered 100 times already." Oh, and "What. no points???"
skt_skt
Honored Contributor

Re: identify the passive and active path in multipath

here is the diff with thr org file

# diff /etc/multipath.conf.orig /etc/multipath.conf
11c11
< devnode "*"
---
> devnode "^(sda|hdc)"
skt_skt
Honored Contributor

Re: identify the passive and active path in multipath

is it possible to diaable a path of a DM device in LVM ?how?
skt_skt
Honored Contributor

Re: identify the passive and active path in multipath

yes, i got the info about the lvm filter

[root@shdbl3d lvm]# diff lvm.conf.orig lvm.conf
52c52
< filter = [ "a/.*/" ]
---
> filter = [ "r|/dev/cdrom|", "r|/dev/hdc|", "r|/dev/sd[bc]|", "r|/dev/disk/by-path/.*|", "a/.*/" ]
skt_skt
Honored Contributor

Re: identify the passive and active path in multipath

I have onlt one HBA connected to the two different SPs and hance only two paths